South Korean President Moon Jae-in will travel to Pyongyang next week for his third meeting this year with North Korean leader Kim Jong-un. Moon’s task, reviving efforts to achieve peace and denuclearization on the peninsula, is a difficult one.

Why Another Summit?

Despite this year’s whirl of high-level diplomacy among North Korea, South Korea, and the United States, there appears to be little progress on North Korean denuclearization.

The two Koreas have followed through on many culture, sports, and humanitarian exchanges contained in this spring’s Panmunjom Declaration, including basketball and tae kwon do events, cultural performances, and family reunifications.

But there’s been little progress on the crux of the declaration, which concerns peace-building and denuclearization. Inter-Korean military talks have borne some fruit, including the removal of some guard posts on the South Korean side of the demilitarized zone (DMZ), but both sides have much more work to do—including North Korea pulling back artillery to positions that reduce the threat to Seoul, and South Korea taking corresponding measures. With confidence-building measures between the two Koreas underway, Moon and Kim will focus on the elusive dual goals of peace and denuclearization.

There is much at stake. A stalemate over denuclearization could push the Trump administration to tighten the economic and military screws on the North. This would put pressure on Seoul to slow down its efforts to boost inter-Korean relations and generate the kind of discord between Washington and Seoul that Pyongyang would love to exploit.

Moon’s Diplomatic Dance

Moon says he will work to “mediate and facilitate” dialogue between the United States and North Korea on “complete denuclearization.” This will not be easy. Kim reportedly feels he has already taken significant steps toward dismantling North Korea’s nuclear arsenal by closing a nuclear test site and missile production site, and he thinks the United States has not reciprocated. Moon will also come under pressure from Kim to ease sanctions soon and begin to implement inter-Korean economic cooperation, starting with railway infrastructure.

South Korea has held discussions on the United States issuing a declaration to formally end the Korean War, which Kim wants as a precondition for discussing the details of denuclearization. At the same time, South Korea has conveyed the U.S. desire for North Korea to declare that it will dismantle the majority of its nuclear facilities, weapons, and fissile material stockpiles. The United States could accept an exchange of declarations, with the North detailing its nuclear and missile production sites as an expression of its seriousness of purpose regarding denuclearization.

What Comes Next?

Moon will travel to New York the week after his meetings in Pyongyang to brief President Donald J. Trump on the sidelines of the UN General Assembly. Moon will share Kim’s thoughts on denuclearization, and Trump will decide whether to reset U.S.-North Korean diplomacy, which likely would involve a second meeting with Kim. Based on the United States’ and South Korea’s assessment of the prospects for diplomatic progress, the two countries’ defense ministers will consult in October and decide whether to resume large-scale joint military exercises.